Introduction: Basilar artery occlusion (BAO) accounts for 1% of all strokes but the mortality rate is high. Bridging approaches combining intravenous (IV) and intraarterial (IA) interventions have improved recanalization rates and patient outcomes. We present an interesting anatomical case of BAO in which the BA could not be endovascularly accessed via the posterior circulation and required retrograde access via the anterior circulation.

Methods: A 62-year-old man presented 3 hours after the acute onset of vertigo, dysarthria, and ataxia. Computed tomography angiography (CTA) demonstrated an occlusion of the mid-BA (Figure 1). IV tissue plasminogen activator (tPA) therapy was initiated, but during infusion the patient developed right gaze preference and became unresponsive. CT of the head was negative for hemorrhagic transformation and the patient proceeded with immediate endovascular intervention.

Results: A left subclavian artery injection demonstrated lack of flow in the BA just distal to the anterior inferior cerebellar arteries. The right vertebral artery terminated as the posterior inferior cerebellar artery (PICA) and the left vertebral artery demonstrated severe proximal tortuosity (Figure 1), thus preventing access to the basilar artery. A left internal carotid artery (ICA) injection showed a large left posterior communicating artery (PCoA) with contrast opacification of the posterior cerebral, distal basilar, and superior cerebellar arteries. A microcatheter was successfully navigated from the left ICA through the PCoA into the distal BA (Figure 2). Mechanical thrombectomy was performed followed by IA tPA administration proximal and distal to the occlusion. Subsequent contrast injection demonstrated partial flow past the previously occluded portion of the BA.

Conclusions: Prompt recanalization of BAO is critical for improving patient outcome and survival. This is often achieved with bridging approaches combining IV and IA interventions. The present patient’s unique anatomy precluded conventional BA access but allowed for retrograde access, resulting in successful recanalization of the BA.

Patient Care: We present an alternative route for endovascular access to an acutely occluded basilar artery in a patient whose unique anatomy precluded access via the posterior circulation.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the incidence and mortality rate of basilar artery occlusion, 2) Describe the treatment options for basilar artery occlusion, 3) Recognize the importance of prompt recanalization of basilar artery occlusion.

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